Tubular knitted fabric

ABSTRACT

A tubular knitted fabric having a closed end at which loops of an end course having a reduced number of wales are drawn together in closed condition is produced on a circular knitting machine having a circular series of independently operable needles by knitting tubular fabric on the needles, transferring needle loops from selected spaced needles to intervening needles to reduce the number of wales and the number of active needles, knitting a plurality of courses on the reduced number of active needles including an end course, passing a closure yarn successively through needle loops of the end course while held on the machine and successively releasing the needle loops of the end course from the machine when the closure yarn has been passed through them while tensioning to draw the successively released loops together so that when the final loop of the end course has been released from the machine the loops of the end course have all been drawn together to form a closure.

United States Patent Hanney et al.

[ Jan. 15, 1974 4] TUBULAR KNITTED FABRIC [73] Assignee: The Bentley Engineering Company Limited, Leicester, England [22] Filed: Oct. 21, 1971 [21] App1.No.: 191,230

[30] Foreign Application Priority Data France 66/189 2,006,394 12/1969 France 66/9 R 1,804,235 7/1969 Germany 66/187 154,974 5/1965 U.S.S.R 66/172 R Primary ExaminerWm. Carter Reynolds Att0rneyRobert E. Burns et al.

57 ABSTRACT A tubular knitted fabric having a closed end' at which loops of an end course having a reduced number of wales are drawn together in closed condition is produced on a circular knitting machine having a circular series of independently operable needles by knitting tubular fabric on the needles, transferring needle loops from selected spaced needles to intervening needles to reduce thenumber of wales and the number of active needles, knitting a plurality of courses on the reduced number of active needles including an end course, passing a closure yarn successively through needle loops of the end course while held on the machine and successively releasing the needle loops of the end course from the machine when the closure yarn has been passed through them while tensioning to draw the successively released loops together so that when the final loop of the end course has been released from the machine the loops of the end course have all been drawn together to form a closure.

7 Claims, 7 Drawing [Figures PATENTEBJAN] 519M SHEET 3 BF 4 FIGS.

PAIENIEnJAm 5 I974 SHEET H []F 4 TUBULAR KNITTED FABRIC The invention is for improvements relating to tubular knitted fabric and provides novel forms of closed tubular fabric structure as well as methods and mechanism for closing such fabric economically. The invention is particularly useful in connection with the formation of toe end parts of tubular knitted articles of hosiery footwear, such as socks, stockings and pantie-hose, and will be described hereinafter in connection therewith.

The invention provides a method of producing an article of tubular knitted fabric having a closed end at which loops in an end course of single ply fabric are drawn together to a closed condition by a yarn or yarns passing through them and pulling them together, and having the number of wales in the fabric reduced at a position or positions before the end closure.

The invention includes a method of producing such an article or closing a tubular knitted fabric on a circular knitting machine, which method comprises reducing by loop transfer the number of wales in the fabric and, while the fabric is retained on needles of the knitting machine, joining the loops in the last course thereof by a yarn or yarns passing through them in turn and drawn taut so as to pull them together to form a closure. The whole operation can be performed on the knitting machine, enabling an effective closure to be performed at the conclusion of a knitting operation, so that the article can be knitted in the orthodox direction from top to toe; no subsequent closing operation being required.

The closure of the tubular knitted fabric may be performed by seaming or linking together the loops remaining on the needles by means of a seaming yarn or yarns drawn taut at the seam to pull the loops together to a closure. The seaming yarn or yarns maybe anchored by being knitted into the fabric before seaming of the closure takes place, and they may be seamed or linked to the loops on the needles in turn and the loops then cast off in turn from the needles.

In an alternative procedure the closure is effected at the conclusion of a knitting operation by causing at least one closing yarn to extend as a single (i.e., unlooped) strand in turn through each of the loops remaining on the needles of the knitting machine, each such loop being cast off its needle as soon as the closing yarn has been passed through it, and the closing yarn being tensioned to draw the loops together in turn so that as the last loop is cast off its needle the closure is completed. The yarn passed through the loops in turn may for example be a main yarn which has been knitted into the fabric and is therefore secured thereto. The procedure of passing the closure yarn through the loops may comprise severing it at a position such as to leave a free length capable of being wrapped round raised needles of a circular knitting machine to an extent greater than a complete turn, organizing the machine so as to knit loops from the free length on successive active needles, one at each successive complete circuit of knitting, and after each loop is knitted pulling one of its legs and the remainder of the free length of yarn through its old loop so as to draw the severed end of yarn therethro ugh and at the same time free the old loop from attachment (through the new loop) to its needle. The last new loop to be formed and eventually released from its needle has the remainder of the free length of yarn pulled through it to seal the closure before being released from its needle to finish casting off the complete garment or fabric tube.

Before the actual closure takes place knitting of the tubular fabric proceeds towards the closure point, being terminated there, and the reduction in the number of wales, with consequent reduction in the width of the tube, may take place in one or more stages by transferring spaced loops (for example alternate loops, or every fourth loop, followed by others at later stages) to needles adjoining those on which they have been formed. Such transfer may be effected by a welt dial. In one such procedure, the welt end, leg and heel parts of an article such as a sock are knitted towards the toe, then a loop transfer occurs to transfer alternate loops from the needles on which they were formed to adjoining needles, thus reducing the number of wales by one half. If a further reduction or reductions should be required this procedure is repeated to halve the number of wales remaining each time. When the number of wales has been reduced sufficiently, knitting is suspended to enable a length of a main yarn, or of a previously introduced auxiliary or seaming yarn, to be drawn from the feeder and cut. The length of yarn is manipulated so as to cause such yarn or yarns to pass in turn through each loop of yarn on the needles forming the last course knitted, and as each stitch of the course re ceives the auxiliary yarn or yarns the stitch is released from the knitting machine. Meantime a constant tension is kept in the length of yarn so that during the progressive release of the stitches of the last course knitted the loops in the wales of the fabric become drawn together and when the final loop has been released the toe opening has been drawn to a closed condition. Finally, the auxiliary or closing yarn is cut adjacent to the fabric to release the footwear article from the machine. The closing yarn or yarns is thus incorporated in the terminal loops of the toe fabric in the manner of a drawstring which is drawn tight to hold the loops together and fastened at its end to prevent unroving.

FIRST PROCEDURE This procedure is described on a circular knitting machine having a cylinder and dial with latch needles in the cylinder and loop holding elements (hooks or latch needles) in the dial. For convenience, the cylinder needles will be referred to simply as needles and the dial hooks or dial needles simply as dial elements. Both the needles and the dial elements are capable of expanding their loops for transfer purposes. The dial can be shogged so that loops transferred from needles to dial elements may, after shogging the dial, be placed on needles other than those from which they were transferred. The machine is also equipped with means for projecting a loop of yarn or thread through the fabric loops held on the machine and locking such yarn or thread in a manner similar to that used when inserting seaming yarns in a linking operation.

The main part of the article has been knitted, and the loops of the last course of the foot (before the toe end part) are around every needle stem. At this first phase every second needle is raised to a height at which its loop is engaged by the loop expander on its stem. The loops are expanded so that they can be penetrated by the dial elements which are serially projected through the loops so that upon subsequent withdrawal of the needles the loops will be left on the dial elements. Upon their withdrawl, these alternate needles are directed to a low inactive track. The dial is now shogged through one needle pitch so that the transferred loops are positioned above the intermediate needles which have their original loops within their hooks. The dial elements are projected to an extent necessary to expand their loops and the intermediate needles are raised through the expanded loops which are now caused to be transferred to the needles by retraction of the dial elements. The intermediate needles are brought to clearing height and then pass through a knitting station where they receive yarn and cast off the transferred loop together with the original loop. Knitting is continued for a few courses and thus a first phase of the shaping of toe fabric is accomplished with loops on only half of the original number of needles.

The second phase is now commenced with loops on every alternate (that is intermediate) needle and all intervening needles without loops retained in a low inac tive track. At this stage every alternate one of the intermediate needles (half of the needles knitting) is raised, transfers its loops to a dial element, and then goes to a low inactive track. The dial is shogged, this time through two needle pitches, and the transferred loops are positioned above the remaining active cylinder needles. These active needles are raised to take the loops from the dial elements, are brought to clearing height, and pass through a knitting station where they receive yarn and cast off the transferred loop together with the previous loop. Knitting is continued for a few courses and thus the second phase of the toe shaping is completed with loops on only a quarter of the original number of needles.

A third phase of toe end formation, the closing step, is commenced by selecting a small group of needles (for example four) so that a seaming or closing yarn or yarns may be fed to them as well as the ground yarn. A suitably disposed seaming device, which may in the present example consist of a reciprocating needle (which supplies one seaming yarn) radially disposed in relation to the needle cylinder, and a co-operating looper which supplies a second seaming yarn, is actuated to supply the seaming yarns to the aforesaid group of needles so that they are knitted in together with the ground yarn and are thereby anchored in the fabric. The ground yarn is then cut and taken out of action so that the knitting action is suspended. At this stage all the loops on the active needles are transferred to the dial elements. This action causes the fabric to be suspended from the dial elements, with the fabric tensioned by air suction or its equivalent so that the transferred loops are disposed in a substantially vertical position. A seaming needle, through which the seaming yarn is fed, is then actuated to project successive loops of seaming yarn through successive fabric loops suspended from the dial elements. A co-operating looper is also actuated to feed a further seaming yarn through the projected loops on the opposite side of the fabric to form a seam of a type which is capable of being tensioned in the manner of a draw string to effect automatic closure of the end of the tapered toe fabric. A lock chain stitch or lockstitch type of seam is suitable.

The seaming operation will commence on the first fabric loop following the group of loops in which the seaming yarns are anchored and thereafter seaming yarns are supplied to successive loops as the machine revolves. The seaming operation is performed with an intermittent, to and fro, circumferential movement (as on a steady dial linking or looping machine) synchronised with the motion of the revolving needle cylinder and dial so that the seaming needle can penetrate each fabric loop as the loops move round with the dial. The fabric loops are progressively engaged by the seaming yarns and are then, in turn, immediately released from the dial elements, commencing with the loops following the group of anchored seaming yarn stitches. A constant tension is maintained in the seaming yarns and a constant pull is exerted on the fabric to draw it away from the machine. Consequently when the loops are progressively released one by one the loops in adjoining wales are drawn together and when the final loop has been released from the machine the loops around the toe end of the sock fabric have all become drawn together to form a closure.

The seaming yarns are finally severed adjacent to the fabric, thus releasing the sock or other article from the machine. It may be desirable, depending on the type of yarn used and/or on the kind of seaming stitch used, finally to lock the seaming yarns or set the fabric, for example by heat or steam, to ensure permanent and run resistant closure.

SECOND PROCEDURE In another procedure, readily performed on a hand operated circular machine, narrowing of the fabric is carried out in three more gradual stages in each of which one loop from each of successive groups of four needles is transferred by one needle space, so that the overall reduction in wales leaves only one quarter of the original wales, the needles left without loops being removed or otherwise rendered inactive. Then when closure is required all needles except the last one to knit are raised to heel height and a length of the main yarn and/or of a previously introduced auxiliary yarn, is severed which is sufficient to wrap round about one and a quarter to one and a half circuits of the circle of raised needles. The severed free length of yarn is then fed so as to be wrapped round the circle of raised needles and knitting is continued but with the modification that only one needle takes and knits the wrapped free length of yarn at each circuit of knitting, this being the needle next following that which last knitted the yarn.

As each needle knits the wrapped free length of yarn extending around the needle circle and casts off its old loop a hooked member is operated to grasp the newly formed needle loop on the outside of the needle circle and cause it to be pulled fully through the old loop and again wrapped around the remaining raised needles. This action draws the free end of the wrapping yarn through the last formed loop and releases the latter from its needle which is thereupon either removed or otherwise rendered inactive.

The procedure is continued until only one loop of the fabric remains on a needle and then a new loop is formed through it from the free length of yarn and the end of the free length is drawn through the new loop whilst on its needle by means of said hooked member or another device to finish off a non-run toe closure. This procedure causes sufficient tension to be applied to the free length of yarn to draw all of the loops in the last row together to close the fabric tube completely.

The invention is illustrated by way of example in the drawings.

FIG. 1 is a perspective view of part of a closed fabric tube as seen looking on to the closed end;

FIG. 2 is a developed view on an enlarged scale of part of the fabric showing its structure and a method of closing it;

FIG. 3 is a view corresponding to FIG. 2 but showing a different structure;

FIG. 4 is a diagrammatic view of the upper end of the cylinder of a circular knitting machine at one stage in the procedure of forming the closed tube of FIG. 3;

FIG. 5 is a view corresponding to FIG. 4 but showing another stage in the same procedure;

FIG. 6 is a greatly enlarged perspective view of a latch needle and part of the needle cylinder showing the drawing of a yarn through a loop in making the closed structure of FIG. 3;

FIG. 7 is a view corresponding to FIG. 6 showing a method of finishing off a closure of the form shown in FIG. 3;

FIGS. 1 and 2 illustrate a construction suitable for the toe end ofa sock and the fabric comprises a portion 10 corresponding to the central part of a foot portion. At the course line 11 there may be a change of yarn to form the toe end part with knitting continuing on all needles up to course line 12 at which loops of alternate ones of the wales 13 are transferred to needles adjoining those on which they were formed to reduce the wales to half the number in the portion of fabric at 14. Again at the course line 15 a further transfer of loops occurs to reduce the number of wales in a portion 16 of the fabric to half the number present in the portion 14 and a quarter of the original number of wales. At the point of closure the end loops of the wales remaining are joined by seaming yarns 17, 18 passed through all of the loops in turn and drawn tightly to bring them together to form the closure, the yarns l7, 18 being cut to leave a short pigtail 19.

FIG. 2 shows a developed view of the stitch structure from which the loop transfers can be seen clearly, and it shows the seaming yarns 17, 18 seen through end loops 20 in the form of a lock stitch seam which for clarity of illustration is shown extended instead of drawn tightly as it would be in practice.

Referring now to FIG. 3 the modified fabric structure shown therein is one in which three transfers of loops occur to reduce the number of wales in the fabric towards the closure' point. First of all at the course line 21 the loop from every fourth needle is transferred to the left thus reducing the number of loops in the next course by one quarter. Again at the course line 22 the loops from every fourth needle (being needles offset by one needle space from those from whichloops were previously transferred) are transferred to the left reducing the total number of wales to one half of the original number. Further at the course line 23 another similar transfer occurs from every fourth needle(th'at is every second remaining loop) bringing the total number of active wales down to one quarter of the original number. At this stage loops of the last course shown at 24 have a joining yarn 25 passed through them which is drawn taut to pull all the loops 24 close together to form the closure. The closure is completed by locking a last loop 25a by turning back the free end of yarn 25 through such loop and drawing it taut as can be seen in FIG. 3. The needles from which loops transferred are thereupon caused to be inactive.

The closure may be effected by the SECOND PRO- CEDURE mentioned above and now described with reference to a hand operated Griswold machine. In

FIG. 4 there is shown a cam box 26, a needle cylinder 27 and latch needles 28. The yarn Y is led towards the needles 28 through a guide 29 carried by a bracket 30 and delivered to them through a feeding hole 31 in a latchguard 32 also carried by the bracket 30. On completion of the course of the loops 24, the needles are in turn brought to heel height as shown at the front and back and to the right of FIG. 4. The course formed by the loops 24 is the first course following the last of the three courses in which loops are transferred as just described, and advantageously before all needles are raised to heel height one needle is caused to be drawn and form a new loop through the first of the loops 24. The feed yarn Y is now lapped as in Y1 (FIGS. 4 and 5) around all the needles at heel height for approximately 1% to 1% turns around the needle circle and is cut to terminate it. This leaves a condition where the garment is suspended from the needles at heel height and the lapped yarn is lying around their stems, the lapped yarn having a free end Y2, FIG. 5, not connected to a bobbin or other form of yarn supply.

The final clsoing operationis as follows: The last needle to have been knitted has its new loop drawn through a single loop and held on its stem below the latch as shown at 33 in FIGS. 4 and 5. The loop 33 is then engaged by a manually manipulated hooked mem ber 34, FIG. 6, or some other suitable means and is drawn out in such a way that the loose end of the lapped yarn is drawn through the previous fabric loop indicated at 24' in FIG. 6, being the loop cleared when the new loop 33 was made from the lapped yarn. The drawing of the yarn Yl completely through the loop 24' may be effected by relative rotation between the needle cylinder 27 and the cam box 26, with the hooked member 34 mounted on the cam by suitable means, not shown. This presents a condition in which the last loop knitted in conventional manner i.e., from a conventionally fed yarn,.is now prevented from run ning back by a single thread (as distinct from a loop) which passes through the last fabric loop knitted and which on being pulled through it releases said last fab ric loop from the needles. Just before the free end Y2 of the lapping yarn Y1 is drawn through the loop 24, the next succeeding needle which retains a stitch is lowered to knitting height with its latch remaining open. Also when said free end Y2 has passed through the loop 24' the related needle indicated at 28' in FIG. 6 is removed or lowered to an inactive position.

On further relative rotation between the cylinder 27 and cam box 26 the yarn Y1 is again lapped around the raised needles after being first fed above the open latch of the needle lowered to knitting height. As the relative rotation occurs the lowered needle knits a fresh loop and clears its old one and then the hooked member engages and pulls out the fresh loop as already described in relation to loop 33. The sequence of actions is then repeated removing the fabric from one needle per relative rotation between the cylinder 27 and cam box 26 until the lapped yarn Yl has been passed as a single (i.e., unlooped) yarn through all except one of the loops 24 leaving the garment suspended from the last remaining needle with all wales having an anti-run bar which has been manually drawn up tightly to the close fabric tube e.g., the toe end of a stocking or sock.

The sequence is repeated once more for the last needle with a modification of procedure to lock the yarn on its last loop. To this end, after knitting the loop from the lapped yarn Y1 and prior to pressing the garment off the last needle, the lapped yarn is drawn by the hooked member 34 or otherwise, from the inside of the cylinder through the new loop to the outside as shown in H6. 7 this having the effect of locking the lapped yarn by passing its end through the last loop indicated at 35.

After finally pressing off the loop 35 from its needle the lapped yarn Y1 may be trimmed short, or trimmed to leave a sufficient length to be drawn to the inside of the garment.

Although the procedure to form the fabric structure of FIG. 3 has been described in relation to a hand operated Griswold machine in which there is a stationary cylinder and rotating cam box, it may equally will be carried out on a machine having a rotary needle cylinder and stationary cam box. The procedure may also be performed on a power driven machine.

What we claim is:

l. A method of producing a circular knitting machine having a circular series of independently operable needles, a tubular knitted fabric having a closed end at which loops in an end course of single ply fabric are drawn together in closed condition, which comprises knitting a tubular fabric on said needles, transferring needle loops of said fabric from selected spaced needles to intervening needles to reduce the number wales and the number of active needles, knitting a plurality of courses on said reduced number of active needles including an end course, passing a closure yarn successively through needle loops of said end course while held on said machine and successively releasing said needle loops of said end course from the machine when said closure yarn has been passed through them, said closure yarn being tensioned successively to draw said needle loops together as they are released from the machine, whereby when the final loop of said end course has been released from the machine the loops of said end course have all been drawn together to form a closure.

2. A method according to claim 1, in which said closure yarn extends as a single (i.e., unlooped) strand through all of said needle loops of said end course.

3. A method according to claim 2, in which one end of said closure yarn is knitted into the fabric while the other end is free thereafter, said machine is operated successively to draw a loop of said closure yarn through each of said needle loops of said end course in turn, and in which after each said loop of closure yarn is drawn it is pulled out to draw the remainder and free end of said closure yarn through the respective loop of said end course and at the same time free said loop of the end course from its needle.

4. A method according to claim 3, in which said closure yarn is drawn through one loop of said end course each rotation of the machine.

5. A method according to claim 1, in which said closure yarn is a continuation of the same yarn of which said end course is knitted.

6. A method according to claim 1, comprising a plurality of said loop transferring operations to reduce the number of needle loops in said end course to not more than one quarter the number of wales of said tubular fabric prior to said transferring operation.

7. A method according to claim 6, in which after each transferring operation a plurality of courses of fabric are knitted before a subsequent transferring 

1. A method of producing a circular knitting machine having a circular series of independently operable needles, a tubular knitted fabric having a cloSed end at which loops in an end course of single ply fabric are drawn together in closed condition, which comprises knitting a tubular fabric on said needles, transferring needle loops of said fabric from selected spaced needles to intervening needles to reduce the number wales and the number of active needles, knitting a plurality of courses on said reduced number of active needles including an end course, passing a closure yarn successively through needle loops of said end course while held on said machine and successively releasing said needle loops of said end course from the machine when said closure yarn has been passed through them, said closure yarn being tensioned successively to draw said needle loops together as they are released from the machine, whereby when the final loop of said end course has been released from the machine the loops of said end course have all been drawn together to form a closure.
 2. A method according to claim 1, in which said closure yarn extends as a single (i.e., unlooped) strand through all of said needle loops of said end course.
 3. A method according to claim 2, in which one end of said closure yarn is knitted into the fabric while the other end is free thereafter, said machine is operated successively to draw a loop of said closure yarn through each of said needle loops of said end course in turn, and in which after each said loop of closure yarn is drawn it is pulled out to draw the remainder and free end of said closure yarn through the respective loop of said end course and at the same time free said loop of the end course from its needle.
 4. A method according to claim 3, in which said closure yarn is drawn through one loop of said end course each rotation of the machine.
 5. A method according to claim 1, in which said closure yarn is a continuation of the same yarn of which said end course is knitted.
 6. A method according to claim 1, comprising a plurality of said loop transferring operations to reduce the number of needle loops in said end course to not more than one quarter the number of wales of said tubular fabric prior to said transferring operation.
 7. A method according to claim 6, in which after each transferring operation a plurality of courses of fabric are knitted before a subsequent transferring operation. 